1/3 c. sugar
1/3 c. cider vinegar
2 tbsp. soy sauce
2 tbsp. sherry
1/4 c. tomato sauce or catsup
2 tbsp. cornstarch dissolved in 1/2 c. reserved pineapple juice

Combine all ingredients in saucepan, cook over medium heat, stirring, until sauce thickened. Remove from heat and set aside.